Lifting boom control device



1, 1.967 E. E. ZIEGLER 3,333,716

LIFTING BOOM CONTROL DEVICE Filed Dec. 28,. 1965 5 Sheets-Sheet 1 1*? wer: tor

29 7%4 4 /%'s flzorney dug Z1. bag/er Aug. 1, 1967 E. E. ZIEGLER LIFTINGBOOM CONTROL DEVICE 3 Sheets-Sheet 3 Filed Dec. 28 1965 frzverrorlaw/27E Z/e United States Patent 3,333,716 LIFTING BOOM CONTROLDEVICE Edwin E. Ziegler, Glen Ellyn, 11]., assignor to General ElectricCompany, a corporation of New York Filed Dec. 28, 1965, Ser. No. 516,9089 Claims. (Cl. 214-130) ABSTRACT OF THE DISCLOSURE A material handlingdevice having an extensible lifting boom carried by a hoist and carriageand controlled by a handle. The carriage is mounted for rotation aboutvertical pivots to accomplish azimuth rotation of the boom. The azimuthmotor is located in the base of the hoist and the boom is pivoted in thecarriage for vertical movement. A hydraulic cylinder mounted between theboom and carriage imparts vertical movement to the boom and anextensible cylinder causes the extensible boom to extend or retract. Ineach motion there is spatial correspondence between the control elementand boom tip and also a diminished force is fed back by lever systemsfrom the boom to the control handle to give feel.

My invention relates to a hydraulically operated boom. This inventionrelates particularly to a hydraulic boom having return feel and hascorrespondence of movement between a control handle and the boom inazimuth and elevation. The apparatus will be described particularly inrelation to a boom but is understood to be equally adapted to remotecontrol of devices such as guns, power shovels or any other extendedmember wherein the characteristics of this invention are important.

In the movements of objects, it is a common occurrence that one wishesto move an object under load. When one wishes to move some objectagainst a force of some sort, it is advantageous to have a feel in thecontrol handle or shaft which corresponds to the amount of force putforth in overcoming the resistance to such movement. It is furtheradvantageous if there is a spatial correspondence between the controlhandle and the object being moved. If both feel and spatialcorrespondence are present in the apparatus, the operators situation ismost analogous to his physically moving the load. In prior art machineswhere these characteristics are absent, the operator must spend time tolearn a new set of relationships between movement and feel of thecontrol handle and the movement of the load.

A chief object of the present invention is to provide a lifting boomhaving a return feel which is a small portion of the force being exertedand having a spatial correspondence between the boom and the controlhandle. With my invention, the operator can position the load withdeftness and accuracy.

Another object of this invention is to provide a system adaptable tocontrol any device pivoted for universal movement.

Another object is to provide a compact easily controllable system forhoisting loads wherein the operators control movements are the same ashe would use in physically moving the load. Thus in an emergency theoperators spontaneous reactions are most likely to be correct.

Another object of my invention is to provide a device capable of doingthe work of one or more men with corresponding less work and fatigue tothe operator.

Another object of this invention is to provide a single control elementor actuator for operating a plurality of operating motors in conjunctionto accomplish the single purpose of moving an object about a pivot.

3,333,716 Patented Aug. 1, 1967 These and other objects will be morereadily perceived from my description which follows.

Briefly stated, my invention is a control device which operates to moveany extended member about a pivot in azimuth or vertically and to changethe length of the extended member. The movements of the extended membercorrespond in direction to the movements of the single control member.In addition, some of the force applied to the extended member is fed tothe control member to give it feel. Thus the extended member moves inthe direction of motion of the control member and some of the forceapplied to the extended member is fed to the control member. In this waythe operator will know the direction of motion of the extended memberand will have an idea of the amount of force being applied to theextended member.

The attached drawings illustrate a preferred embodiment of my inventionin which:

FIGURE 1 is a perspective view of an embodiment of my invention andshows a perspective view of a preferred embodiment of my inventionwherein the system is used as a refrigerator handling apparatus.

FIGURE 2 is a view taken along line A-A of FIG- URE 1.

FIGURE 3 is a block diagram showing the organization of the system. 1

FIGURE 4 is a perspective view of the mechanism of my invention inskeleton schematic diagram.

In FIGURE 1 is shown an automatic hoist with an operator. This hoist isused for moving refrigerators or similar objects about, perhaps in afactory.

The boom 1 of this hoist is moved in its vertical direction about apivot point on the carriage element by the cylinder 2. Azimuthorientation of the boom is accomplished by rotation of the boom aboutthe vertical axis B as carriage 3 rotates about a vertical axis on pivotpoints located in the body of the hoist. In this way the carriage 3 isfree to be rotated about these pivot points clockwise andcounterclockwise. The hydraulic motor to rotate the carriage willnormally be located in the base 4 of the hoist so that torque can beimparted to the carriage element. As shown, the vertical liftingcylinder 2 is fastened between the carriage and boom. Thus extensionmoves the boom in a vertical direction about a pivot in the carriage.The hydraulic pump (not shown) and servo units for vertical, extensionand rotary movements can be located in the base 4 of this lift.

The block diagram of FIGURE 3 shows the elements of the operating systemand their relationships in a general Way. The system is divided intoessentially three different control systems.

First, the vertical control system starts from the control member 5 andcontrols the boom in vertical movement. The control handle or member 5operates a linkage between the shaft and valve. This linkage causes thevalve element of a servo valve to operate a power element of the servovalve. The valve power element allows hydraulic pressure to be appliedon a selective basis to the vertical cylinder and moves the piston inthecylinder. Attached to the vertical cylinder, as shown in FIGURE 1, isthe boom. Attached to the boom near its pivot point is a force reducinglinkage which in turn applies a much reduced force back into the controllever so that the operator may have a feel in the control lever in avertical direction.

In a somewhat similar manner, the control handle operating in azimuth,from right to left as'shown in FIGURE 1, operates a servo valve orvalves to cause a reversible hydraulic motor to turn the boom andcarriage in a clockwise or counter clockwise direction. The forceapplied to the carriage affects a force reducing linkage connected tothe control handle. The force reducing linkage gives the control handlea feel in azimuth.

By the means described above, the operator is able to control the boomin three dimensions.

The boom and carriage provide a connection between the two systems. Thisconnection is shown schematically by the boom being shown within thecarriage. Also, a connection is provided by the control handle to whichboth systems are mechanically coupled.

Finally, the extension system is operated by the handle 5 moving forwardor back and causing servo valves to allow hydraulic pressure to beapplied to a cylinder and causes extension or contraction of thecylinder. The boom is extended or shortened as the piston moves in thecylinder. Feel is imparted through a force reduction linkage whichapplies a part of the extension force to the control handle.

FIGURE 4 illustrates details of the three actuators. It is realized thata variety of possible arrangements are possible utilizing the sameprinciple. The elevator actuator or hydraulic cylinder 7 is shown (FIG.4) pushing against or pressing against the short arm of a lever 8. Inpractice, this short arm of a lever can be a cam arrangement and the camis fastened through a shaft to the long 7 arm of the lever. Thus, inpractice, the elevator actuator presses directly against a cam on theboom rather than at the end of a lever. Thelever action however, ispreserved by means of the cam.

The first lever 8 operates through a link 9 against second lever 10 andthis in turn operates through levers 11 and 12, against the controlhandle 5. The linkages shown in FIGURE 4 thus operate to apply about ofthe force from the elevator actuator to the control handle. As the boomis moved vertically from place to place, the force required to move itis reflected back into the control handle thus giving feel. The first,second and third lever arms may have a series of holes in each arm. Byconnecting the links between difierent holes, ratios can be varied togive a greater or lesser feel.

Attached to the control handle are also link 13 and lever 14 whichoperate the control valve 15. This valve operates to feed controlpressure to the elevation actuator when it is desired to raise the boom.Similarly, if it is desired to lower the boom, the valve allows therelease of fluid from the elevation actuator.

An electric motor and fuel pump (not shown) are located in the base ofthe hoist and contribute pressure selectively through the valves.

The position of the control handle 5 is related to the position of theboom; however, there is not a one-to-one correspondence of position.Rather, the control handle may move through about 10 or 15 degrees whilethe boom is moving through 50 or more degrees.

Movement of the control handle 5 from right to left causes the rotatablecarriage to pivot about its vertical axis. The boom is carried alongwith the carriage and the end of the boom will swing in a wide circle.The rotatable element is designed to swing 90 clockwise and 90 counterclockwise froma central position making a total swing of 180.

The lever and link system shown (FIGURE 4) operates in a similar mannerto that shown in the elevation control schematic. Again, the valve 16 ismounted on the carriage and is actuated through a lever system havingvariable links. Movement of the control handle to right actuates thisvalve so as to feed fluid to the rotatable motor 17 and cause thecarriage to move in a clockwise or counter clockwise direction. A rotaryhydraulic actuator of the type called Flo-Tork and sold by Flo-TorkInc., of Orrville, Ohio, can be used, if desired.

As in the elevation control system, a force reducing means is foundhere. The force reducing lever system shown reduces the force on thehandle to about 6 of the force applied to the boom. This is enough tosupply a feel to the operator. As shown, the level arm 18 extends fromthe boom which is pivoted at 19. Force is transmitted through forcereducing levers 20, 21 and connecting links 22, 23, and 24 to thecontrol handle.

The extension control system operates in a manner similar to theelevation and azimuth systems. In this system, movement of the handle 5moves rack 25. Gear 26 moves gears 27 and 28. Since gear 29 does notmove the spider and planetary gear 28 rotates and opens servo 30. Servo30 allows hydraulic pressure to feed to cylinder 31 and boom element 32slides in or out as moved by the cylinder. Rack 33 will move pinion 34and gear 29 to restore the spider and planetary gear 28 to neutral.

The extension force reducing system, shown here, lever 35 and pivots 36,37 and 38 reduce the extension force on the handle to about of the forceapplied to the slidable boom. The extension system is connected to theazimuth and vertical system by the control handle 5 which slides forwardand back over the control shaft 6.

One of the important features of my invention is that the azimuth forcereducing means and the vertical force reducing means are connected toone end of the control member while the extension force reducing meansis connected to the other end of the control member.

The showing of FIGURE 4 is expanded and schematic so that the componentsof the apparatus can be exposed in a form easily understood. Electrical,hydraulic or mechanical systems can be used interchangeably withoutdeparting from the scope of the invention.

Although it is readily apparent that several embodiments of theinvention may exist, this invention is not limited thereto since manymodifications may be made by one skilled in the art, and it is intendedby the appended claims to cover all such modifications as fall withinthe true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A material handling device comprising in combination a control memberhaving a control shaft and a control handle slidable on said controlshaft,

an extensible boom having an extensible section slidable in anon-extensible section,

means actuated by said control member for applying force to said boom inazimuth,

force reducing means for applying a force equal to a predeterminedportion of the azimuth force to the control member, means actuated bysaid control member for applying force to said boom in a verticaldirection, 7

force reducing means for applying a force equal to a predeterminedportion of the vertical force to the control member,

means actuated by said control member for applying moving force to apart of said boom to change the length of said boom,

force reducing means for applying a force equal to a predeterminedportion of the change of length moving force to the control membercomprising a lever with one end pivoted to said non-extensible section,the other end pivoted to said control handle and an intermediate pointserving as the anchor point for said length changing means for applyingforce to said movable section.

2. A control device as recited in claim 1 in which said extensible boomis pivoted about a horizontal axis in a carriage which swings in azimuthabout a vertical axis in response to said azimuth force applying means,and said azimuth feedback means comprises a series of levers fulcrumedfor force reduction and operatively connected between said boom and saidcontrol handle.

3. A control device as recited in claim 1 in which one end of ahydraulic piston is attached to said movable section and the other endis attached to said anchor point of said lever so that movement of saidhydraulic piston moves said movable section, a first rack attached tosaid movable section, a second rack attached to said control handle anda differential gear means movable in accordance with difference ofmotion between said first and second rack for controlling the movementof said hydraulic piston.

4. A control device for moving an extended member comprising a controlmember having a control shaft and a control handle slidable on saidshaft,

an extensible boom,

means actuated by said control member for applying force to said boom ina vertical direction,

force reducing means for applying a force equal to a predeterminedportion of the vertical force to the control member,

means actuated by said control member for applying moving force to partof said boom to change the length of said boom,

force reducing means for applying a force equal to a predeterminedportion of the change of length moving force to the control member,

means actuated by said control member for applying force to said boom inazimuth,

force reducing means for applying a force equal to a predeterminedportion of the azimuth force to the control member comprising a seriesof levers connected to each other and fulcrumed for force reductionbetween said boom and said control handle.

5. A control device as recited in claim 4 in which said vertical forcereducing means comprises a series of levers connected to each other andat one end of said series to the control shaft and at the other end tothe vertical force means and fulcrumed to reduce the force feedback from:the vertical force means to the handle.

6. A control device as recited in claim 5 in which said extensible boomhas an extensible section slidable in a non-extensible section, and

said azimuth force reducing series of levers is attached at one end tosaid non-extensible section and at the other end to said control shaftso that motion in azimuth is transmitted therebetween. 7. A device formoving an extended member comprising a control member, an extensibleboom,

means actuated by said control member for applying force to said boom inazimuth,

force reducing means for applying a force equal to a predeterminedportion of the azimuth force to the control member,

means actuated by said control member for applying moving force to apart of said boom to change the length of said boom,

force reducing means for applying a force equal to a predeterminedportion of the change of length moving force to the control member,

means actuated by said control member for applying force to said boom ina vertical direction,

force reducing means for applying a force equal to a predeterminedportion of the vertical force to the control member, comprising a seriesof levers connected to each other and at one end of said series to thecontrol handle While the other end is connected to the vertical forcemeans and fulcrumed to reduce the force feedback from the vertical forcemeans to the control member.

8. A control device as recited in claim 7 in which said change of lengthforce reducing means comprises a lever connected at one end of saidextensible boom, at the other end to said handle and fulcrumed to reducethe change of length force as applied to the handle.

9. A control device as recited in claim 8 in which said control membercomprises a control handle slidably mounted on a control shaft and saidazimuth and vertical force reducing means are attached to said controlshaft and said length changing force reducing means is attached to saidcontrol handle.

References Cited UNITED STATES PATENTS 2,536,724 1/1951 Clay 214-2,846,084 8/1958 Goertz et al 2l4l 3,087,636 4/1963 Weaver 2141413,241,687 3/1966 Arloff 214-1 HUGO O. SCHULZ, Primary Examiner.

1. A MATERIAL HANDLING DEVICE COMPRISING IN COMBINATION A CONTROL MEMBERHAVING A CONTROL SHAFT AND A CONTROL HANDLE SLIDABLE ON SAID CONTROLSHAFT, AND EXTENSIBLE BOOM HAVING AN EXTENSIBLE SECTION SLIDABLE IN ANON-EXTENSIBLE SECTION, MEANS ACTUATED BY SAID CONTROL MEMBER FORAPPLYING FORCE TO SAID BOOM IN AZIMUTH, FORCE REDUCING MEANS FORAPPLYING A FORCE EQUAL TO A PREDETERMINED PORTION OF THE AZIMUTH FORCETO THE CONTROL MEMBER, MEANS ACTUATED BY SAID CONTROL MEMBER FORAPPLYING FORCE TO SAID BOOM IN A VERTICAL DIRECTION, FORCE REDUCINGMEANS FOR APPLYING A FORCE EQUAL TO A PREDETERMINED PORTION OF THEVERTICAL FORCE TO THE CONTROL MEMBER, MEANS ACTUATED BY SAID CONTROLMEMBER FOR APPLYING MOVING FORCE TO A PART OF SAID BOOM TO CHANGE THELENGTH OF SAID BOOM, FORCE REDUCING MEANS FOR APPLYING A FORCE EQUAL TOA PREDETERMINED PORTION OF THE CHANGE OF LENGTH MOVING FORCE TO THECONTROL MEMBER COMPRISING A LEVER WITH ONE END PIVOTED TO SAIDNON-EXTENSIBLE SECTION, THE OTHER END PIVOTED TO SAID CONTROL HANDLE ANDAN INTERMEDIATE POINT SERVING AS THE ANCHOR POINT FOR SAID LENGTHCHANGING MEANS FOR APPLYING FORCE TO SAID MOVABLE SECTION.